I have an iMac from 2006 with an Intel Core2Duo, which is 64-bit.
I have also found I am using a 32 bit EFI:
$ ioreg -l -p IODeviceTree | grep firmware-abi | | "firmware-abi" = <"EFI32">
I want to know if I can still install a 64-bit Linux distro. I do not want to dual-boot, just use the Linux. I burned a Linux Mint 18.3 x64 onto a DVD after running the compiled c-program from this tutorial on it: https://mattgadient.com/2016/07/11/linux-dvd-images-and-how-to-for-32-bit-efi-macs-late-2006-models/
But on startup, when pressing OPTION I see only the MacOS-installation as boot-option. Can I do anything about that? Boot with special parameters or something?
I tried booting a 10 year old Knoppix I had lying around here and it was booted successfully, so the DVD drive is still ok.
I also erased the boot-cache with OPTION+COMMAND+P+R, but no success.